Progress Toward Rotavirus Vaccines

Published in Science, this 2-page paper articulates a strategy for vaccination against rotavirus, a common childhood infection that infects children in both industrialised and developing countries in the first few years of life. Rotavirus infections cause diarrhoea and vomiting that is often mild, but can be severe enough to require hospitalisation (e.g., of 55,000 to 70,000 in the United States). Each year, the disease results in about 600,000 deaths among children worldwide.

As reported here, new live oral preparations developed by Merck and GlaxoSmithKline (GSK) recently completed safety and efficacy testing in clinical trials. The authors focus specifically on the February 21 2006 vote on the part of the U.S. Centers for Disease Control and Prevention (CDC)'s Advisory Committee on Immunization Practices to recommend universal vaccination of infants in the United States against rotavirus diarrhoea, following "a 7-year saga about vaccine safety". Within industrialised countries such as this one, communication challenges may emerge due to the fact that the vaccine will initially be expensive, and the health burden of rotavirus is less well appreciated. The authors note that it is also not known whether and to what extent an adverse event (intestinal obstruction) associated with an earlier "Rotashield" vaccine will influence the perception of providers and parents: "concerns might linger until additional safety data are available through postmarketing surveillance in large numbers of children."

In the economically poorest countries of Asia and Africa, it is unclear whether these live oral vaccines will prove as effective as they have in industrialised countries; factors such as maternal antibodies, breast-feeding, interference by other enteric pathogens, and malnutrition might adversely affect the processing of these vaccines in infants in the developing world. Once proven effective in these countries, the authors note that coalitions such as the Global Alliance for Vaccines and Immunizations (GAVI) will have a role to play by carrying out research and communicating results, such as by:

• providing policy-makers with data to determine the value and resources needed to finance the introduction of the vaccine and to identify mechanisms to ensure an adequate and affordable supply; and
• building the evidence base to evaluate vaccines through disease surveillance and key clinical trials, communicating these data to decision-makers and the public, and developing vaccine demand forecasts.

High-level officials are also getting involved in efforts to promote the new vaccine. For example, the president of Panama, Martin Torrijos, himself administered vaccine to an infant on the occasion of the national launch of the rotavirus vaccine in Panama on March 14 2006.